This invention relates to a solvent composition. In a more particular manner, this invention concerns itself with a solvent mixture particularly adapted for use in dissolving and removing cured polysulfide and silicone rubber coatings, sealant, paints and encapsulants from metal substrates.
Polysulfide rubber compositions, as well as silicone rubber compositions, are a well known class of polymeric resins that find wise use as protective encapsulants for electrical and electronic components. However, in order to effect the repair and maintenance of these components; it often becomes necessary to remove the encapsulated coatings. Unfortunately, previous attempts at dissolving and removing such sulfides and silicone rubbers required the use of strong organic acid solvents coupled with severe grinding or abrasion efforts. Oftentimes, the use of severe grinding and strong solvents resulted in extensive damage to the electronic component. As a consequence, repair of the component became a practical impossibility resulting in economic loss due to the fact that the component had to be discarded.
In order to avoid economic losses as well as health and safety hazards due to the use of strongly corrosive acid solvents, it was found necessary to develop a solvent mixture that would prove effective in dissolving and removing polysulfide and silicone rubber formulations from electronic components whether in the form of a coating or protective encapsulant. As a consequence, the solvent mixture of this invention was developed and found to be effective in dissolving such coatings due to its ability to catalytically depolymerize the silicone and polysulfide rubber formulations. The efficient removal of these rubberized formulations from electronic components, fuel tanks and other structural elements provided an effective means for the repair and maintenance of a variety of aerospace systems, thus eliminating, to a great extent, the high cost encountered in previous maintenance programs.